Automatic exhaust, gas filling, and operating circuit control



May 20, 941. H. GREEN mt 2 2 2,465

AUTOMATIC EXHAUST GAS FILLING, AND OPERATING CIRCUIT CONTROL Filed D80.30, 1938 2 Sheets-Sheet l INVENTOR MMWWL ATTQ R N EY y 1941- J. H. GREENETAL, 2,242,465

AUTOMATIC EXHAUST, GAS FILLING, AND OPERATING CIRCUIT CONTROL Filed Dec.30,. 1938 2 Sheets-Sheet 2 TEMPLE? F R INVENTOR M v ATTORNEY araunvmTIME/ 2 Patented May 20, 1941 AUTOMATIC EXHAUST, GAS FILLING, ANDOPERATING CIRCUIT CONTROL James H. Green, West Orange, and George H.

St. John, Bloomfield, N. 1., assignors to Westinghouse Electric &Manufacturing Company, East Pittsburgh, Pa, a corporation ofPennsylvanla Application December so, 1938, Serial No. 248,190 14Claims. 4 (01. 176-2) This invention relates to apparatim forautomatically controlling the exhaustion and gasiilling of electricaldevices, such as gas-filled lamps, rectifiers and other electrical ordischarge devices, and more particularly, to means whereby such devicesare automatically evacuated, flushed and filled with a gas at apredetermined pressure and, during the manufacturing operations, theseasoning or operating current thereto is controlled without manualadjustment.

The principal object of our invention, generally considered, is thesubstitution of automatic control for hand processing of gas-filleddevices, such as discharge lamps and rectifiers.

-Another object of our invention is to secure uniformity in theproduction, and reduction in shrinkage, when manufacturing gas-filledelectrical discharge devices.

A further oblectof our invention is the control of the exhaust scheduleused in the manufacture of rectigons, and other gas-filled electricalde-. vices, whereby all the operator needs to do, with the exception ofthe baking which requires some manual attention, is to insert theexhaust tubes of the devices into the exhaust rubbers, make the cathodeand anode connections, then push a button, and the machine will thenexhaust, flush and fill to a predetermined pressure, while making thenecessary circuits and controlling the current therethrough, until thedevices are finally treated manufacturing other gas-filled electricaldischarge devices. Each of the tubes or bulbs has an exhaust tube i8fitted in an exhaust rubber I! of the vacuum and gas-filling manifold2i.

The manifold 2! has a pipe 22 leading thereto, and controlled by a valve23 operated by a motor 24 as by means of a wheel 25 on the valve stem 26meshing with a pinion 21 on the armature shaft 28. This motor isoperated by apparatus and control circuits generally designated as A,which will be subsequently described, so that it opens and closes thevalve 23 at intervals, to effect the desired exhausting operations forpredetermined periods of time.

The manifold 2! also has a gas admission pipe 28 controlled by a valve3i operated by motor 32. The motor 32 opens and closes the valve throughengagement between a pinion 33 on its armature and filled with gas atthe desired pressure, whereupon the operator merely needs to tip-offtocomplete the process.

Other objects and advantages of the invention, relating to theparticulararrangement and construction of the various parts, will become apparentas the description proceeds.

Referring to the drawings illustrating our invention:

Figure 1 is a diagrammatic view showing a series of rectifier tubes,generally called "rectigons," on an exhaust manifold, and apparatus withassociated circuits for exhausting and gas filling automatically, andconnections to said circuits.

Figure 2 is a view supplementing Figure 1, insofar as circuits areconcerned, as indicated by the common line :c-m' on both figuresindicating the place of connection between the conductors thereof,showing the wiring connections to the rectigons, illustrated in Figure1, and the tem-- plet used in connection with the sequence timer.

Figure 3 is a diagrammatic view showing the sequence timer, includingthe means for operating the templet shown in Figure 2.

Referring to the drawings-in detail, like parts being designated by likereference characters, there is shown a series of. tubes I i to II,inclusive, in the present embodiment represented as rectigons," althoughthe apparatus is adapted for shaft 34 and a wheel 35 on the valve stem36. The apparatus and circuits generally designated as B,

controlling the opening and closing of the gas.

inlet valve 3i, in accordance with the desired pressure, will besubsequently described.

During evacuation, the devices II to H, inclusive, are baked in an ovendesignated by the reference character 31, said oven being so mountedthat it may be lowered over thetubes during the baking operation andraised thereabove after said operation is completed.

Each rectigon is in the present embodiment shown as comprising a hotcathode 38 and an ing the devices I i to II, inclusive, a dischargecur-.

rent is passed therethrough in series, the initiation and intensity ofsaid current being controlled by apparatus and circuits generallydesignated by the reference character D, to be described more fullyhereinafter.

In order to effect the operation of the various parts of the apparatusat the proper time, we provide live! photo-cells, 49, 5|, 52, 53 and 54,operated at the proper times by light emitted from slits II to 59,inclusive, in a templet 8i, which is moved as by means of a motor 62 ofthe synchronous type, past an opening or aperture 63 in a compartment 54enclosing a lamp or other source of actuating light -65. The cells 49and SI operate through apparatus A to respectively open and close vacuumvalve 23, the cell 52 operates through apparatus B to open the gas valveII, the cell 53 operates through apparatus C to close actuate the motorand control the circuit through the filaments, and the cell 54 operatesthrough apparatus D to close and control the plate circuit.

The steps in the exhaust schedule contemplated for the apparatus, suchas the rectigons? II to IT, inclusive, which steps are automaticallycontrolled by the apparatus mentioned to the extent indicated, are asfollows:

1. The operator takes each rectigon, or other discharge device to bemanufactured, and inserts the tube l8 thereof into the appropriateexhaust rubber |9 in order to connect it to the manifold 2|.

2. The lead wires to the cathodes 38 and anodes 39 are then connected tothe source of current, originating at the line connections 55 and 51,and shown in the present embodiment as 110 volts, 60 cycles, A. C., sothat the cathodes 35 may be heated from the secondary windings of thetransformer 48 and a discharge current may pass from said cathodes tothe anodes, in series through all the tubes by virtue of the connectionsshown in Figure 2.

3. After the tubes have been connected as shown in Figure 2, theoperator starts the timer by pushing a button or closing a switch tooperate the motor 52, causing the control templet to be moved along sothat the slits 55 to 59, inclusive, transmit light to actuate the cells49, '52, 53, and 54, in the desired order. The first operation will bethe actuation of the photo-cell 49, to open the valve 23 and exhaust therectigons I to H, inclusive, to the desired extent, that is, forexample, to two microns or better.

4. The oven 31 is then lowered over the rectigons in order to bake thetubes thereof, at temperatures gradually increasing to 500 C. over aperiod of ten to fifteen minutes, after which the oven is raised and thetubes allowed to cool.

5. The movement of the templet 5| now actuates the photo-cell 53 tolight the filaments 35 by means of control apparatus C.

6. Further movementof the templet 5| brings a slit 55 into registry withthe opening 53to operate cell 5| and close the exhaust valve 23, andthen a slit 51 into registry with said opening to operate cell 52 andopen the gas valve 3|, flushof argon.

'7. When the desired argon pressure has-been reached, the gas valve 3!is shut off by means of, the decreased resistance of the filament inthe.

, ratus D to operate.

9. After the plate current has been on for thirty or aboutthirty-seconds, as will be determined by having a slit 59 in the templet5| of 'a lengthcorresponding with the movement of the templet duringthirty seconds, it is then turned off by passage of the end of theslit'beyo'nd the lightopening 53. For example, if the templet isoperated at a speed of 2" per minute, then the slit 59 will be 1" long.

10. A further movement of the templet 5| brings another slit 55 intoregistry with the light passage 53, causing the photo-cell 49 to again24 and open the valve 23, ex-- ing the tubes to a pressure of 13 orabout 13 mm.

hausting the rectigons H to IT, inclusive, to a pressure of one micronor better. When this has been effected, the slit 55 passes beyond thelight aperture 53 and the next slit 55 comes into registry with saidlight aperture, actuating the photo-cell 5| to cause the same apparatusA to operate the motor 24 to close the valve 23 and cut off the vacuumsystem from the rectigons l to H, inclusive.

11. Further movement of the templet 5| brings another slit 51 intoregistry with the light aper-- ture 53, causing the photo-cell 52 toagain operate the motor 32 to flush the tubes II to H, inclusive, withargon to a pressure of six or about six millimeters. This change offilling pressure iseifected by virtue of a new and increased setting ofthe resistance 14, caused by the snap switch 15 having been turned bythe motor 32, so that the Pirani tube 59 is balanced sooner thanpreviously and, therefore, operates quicker to turn off the gas controlvalve 3|.

12. A still further movement of the templet 5| brings another slit 59into registry with the opening 53 to again operate cell 54, and throughapparatus D, turn on the plate current, which again causes a dischargethrough the rectigons to H, inclusive. This time the current is allowedto operate for seventy-five or about seventy-five seconds, as will bedetermin-edby the length of the slit 59 after which it is turned off.

13. The templet 5| then brings another slit 55 into registry with thelight passage 53, causing the photo-cell 49 to again actuate the motor24, through apparatus A, and open the valve 23, exhausting therectigons" H to IT, inclusive, to a pressure of /2 micron or better.When this has been effected, the slit 55 passes beyond the lightaperture 53, and the next slit 55 comes into registry with said lightaperture, actuating the photocell 5| to cause the same apparatus A tooperate the motor 24 to close the valve 23 and cut off the vacuum systemfrom the tubes II to II, inclusive.

14. Additional movement of the templet 5| brings another slit 51 intoregistry with the light aperture 53, causing the photo-cell 52 to againoperate the motor 32 to flush the tubes II to IT, inclusive, with argonto a pressure of six or about six millimeters, as heretofore, it beingnoted that even though the snap switch 15 has been turned another notch,the resistance 14 is still maintained in the same setting so that thePirani tube is balanced after the same length of time, as previously,and on operating to turn off the gasemitting valve 3| leaves the fillingas at the de- 4 sired pressure.

' 15. Further movement of the templet 5| brings another slit 59 intoregistry with the opening 53 to again operate cell 54, and turn on theplate current which causes a discharge through rectigons II to H,inclusive. This discharge is allowed to continue for one hundred andtwenty or about one hundred and twenty seconds, as will be determined bythe length of the slit 59.

16. Before the present slit 59 has passed beyond the light aperture 53,another slit 55 comes into registry with said light aperture, causingthe photo-cell 49 to again actuate the motor 24 and open the exhaustvalve 23. After this exhausting operation has been continued for liveseconds, or about flve seconds, the slit 59 passes beyond the lightaperture 53 to turn off the plate current supp y.

17. The slit 551s of such a length that the "rectigons to H, inclusive,are evacuated to one half micron or less when said slit 55 passesenergize the cell 52 and causes the motor 82 to open the valve 8I toallow the final fill gas to flow to the rectigons" II to I1, inclusive.The pressure of the gas is determined by the type of rectigons.beingmanufactured, that is, sixty-five millimeters is used for low voltagerectigons," and seventy-five millimeters for high voltage rectigons. If,for example, the former are being manufactured, the switch 18 is movedfrom the position indicated in full lines to that shown in dotted linesin Figure l, to correspondingly increase the resistance 18 to make themotor 82 shut off the valve 8I when a pressure of sixtyfive millimetersor about sixty-five millimeters of argon is obtained. If, however, highvoltage rectigons" are being manufactured, the switch 18 is left asshown in full lines, whereupon the valve 8| is left open foracorrespondingly longer time or until a pressure of seventy-fivemillimeters is obtained. The change from the previous setting of sixmillimeters is, of course, effected by a further turn of the snap switch15.

20. When the desired pressure, in accordance with the setting of theswitch 18, has been obtained in the rectigons" II to I1, inclusive, themotor 82 shuts the valve 8I leaving said "rectigons" ready for sealingoif, which is accordingly effected in theusual manner.

The foregoing explanation of how an exhaust schedule may be madeautomatic will now be supplemented by a description of how theapparatus, respectively designated as A, B, C, and D, works.

First considering apparatus A which effects the operation of the motor28 to turn on or off the vacuum valve 28, we find that it is connectedto the controlling photo-cell 88 for opening movement of the valve 28 byconductors l1 and 18 which lead directly to the relay tube 18. Thecathode 8I of the photo-cell 88 is connected to the grid 82 of the tube18 by means of said conductor 18. The plate 88 of the tube 18 is,therefore, connected to the anode 88 of the photocell 88 by means ofconductor 11. The cathode heating filament 88 of the tube 18 isenergized from a secondary winding 88 of transformer 81,

the primary 88 of which is connected to the line conductors 88 and 81 byconductors 88 and 88 respectively. The grid 82' is biased with respectto the cathode 8I by means of secondary winding 82 connected theretothrough a condenser 88 and grid leak 88.

In operation, when the cathode II of the cell 88 starts to emitelectrons upon the impingement of light thereon, the tube 18 passes moreplate current induced by secondary winding 88 of the Dunco relayarmature I82, lead I88, relay armature 81, and lead 88 to line conductor81. The armature I82 is kept in its uppermost position during thisoperation, by current from lead 88, through resistance I88, magnetwinding 88, lead I88, relay armature I82, conductor I88, and back toline 81 through conductor 88.

Apparatus A is also connected to the photocell II for effecting closingmovement of the valve 28. This photo-cell is connected to the relay tubeI88 by conductor I88 from its cathode I81, and conductor I88 from itsanode I88, the cathode I81 being, as in the previous instance, connectedto the grid I I Land the anode connected to the plate H2. The cathodeheating filament I I8 of the tube I85, is energized from a secondarywinding I I8 of transformer II5, the primary II8 of which is connectedto the line conductors 88 and 81 by conductors 88 and 88, respectively.The grid I I I is biased with respect to the cathode I I1 by means ofsecondary winding I I8 connected thereto through a condenser H8 and gridleak I2I.

In operation, when the cathode I81 of the cell 5| starts to emitelectrons upon the impingement of light thereon, the tube I85 passesmore ,pl-ate current induced by secondary winding I22 of the transformerII 5, causing the winding of relay magnet I28 to draw the armature I28thereof to short circuit the winding of the Dunco relay magnet 88through conductors I88 and I25. This allows the armature I82'of saidmagnet to drop from its uppermost position, opening the circuit throughthe "open lead 88 and closing the circuit through the close lead I28.

The operating circuit to the motor 28 for closing movement of the valve28 is from line conductor 88 through conductor 88 to common" lead I8I,motor 28, close" lead I28, armature I82, conductor I88, and back to line81 through conductor 88.

Apparatus B is operated for opening the gas valve 8I in a similarmanner. The cathode I28 of the controlling photo-cell 52 is connected tothe grid I28 of relay tube I8I by means of conductor I82, and the anodeI88 of the cell 52 is connected to the plate I88 of said tube I8I bymeans of conductor I85. The cathode heating filament I88 of the tube I8Iis energized from a secondary winding I81 of transformer I88, theprimary I88 of which is connected to the line conductors 88 and 81 byconductors I8I and I82, respectively. The grid I28 is biased withrespect to the cathode I88 by means of secondary winding I88 connectedthereto through a condenser I85 and grid leak I88.

In operation, when the cathode I28 of the tube 52 starts to emitelectrons upon the impingement of light thereon the tube I8I passes moreplate current induced by secondary winding I81 of the transformer I88,causing the winding of relay magnet I88 to draw the armature I88 thereofto close a circuit from the line conductors 88 and 81 through conductorsI8I and I82 and winding of Dunco relay magnet I58 to raise the armatureI88 thereof and close circuit through open" lead I- to motor 82.

The operating circuit to the motor 82 for opening movement of the valveII is from line conductor 88 through conductor I8I, relay armature I88,lead I58, armature I58, open lead I88, motor 82, "common" lead I81, andback to the line 81 through conductor I82. The armature I88 is kept inits uppermost position during this operation by current from lead I82,through resistance I55, magnetwin'ding I55, lead I55, relay armatureI54, conductor I55, and back to line 55 through conductor l4l.

'Apparatus B is also operated for closing the gas valve 5l when the gasin the manifold 2l, as measured by the Pirani tube 55, reaches apredetermined pressure. Inasmuch asthe schedule described requirespressures some of which are different, means are necessarily providedfor changing the setting of the resistance 14 during the exhausting,flushing and filling opera- The setting, in the present instance, issuch that during the first opening movement of the motor 52, the snapswitch eflects a cutting out of the lower resistance section I50 throughits lead l5l. The circuit during that part of the flushing operationpreviously described in paragraph numbered 6, is preferably from a 7.5volt D. .0. line conductor I52 through "common" conductor I55, snapswitch 15, conductor l5l, the remainder of resistance 14, andmiiliammeter relay 12 to the other corner I54 of the Wheatstcne bridge55. In other words, the resistance 14 is so adiusted that the resistanceof the filament in the Pirani tube 55 balances therewith when a pressureof 13 mm. of argon is in the manifold 2 I.

The subsequent flushing or gas-filling steps are the same as thatpreviously traced, except that for a pressure of 6 mm. of argon, thesnap switch selects conductor I65, and then conductor I55 upon saidswitch being turned another quarter of a revolution. Upon turning stillanother quarter of a revolution, the switch selects conductor I51 whichcuts out still more to cause the resistance 14 to balance that of thefilament in the 'Pirani tube 55 when the pressure of argon is 65 or 75mm., depending on whether the settin of the switch 15 is as shown indotted lines or In full lines;

In the operation of closing the' valve 5| upon the Pirani tube 55balancing the resistance 14, say in the first setting of the snapswitch15, that is. when the pressure in the manifold reaches 13 mm. ofargon, current from the 7.5 volt D. C. source flows through theconductor I52 to one corner of the Wheatstone bridge 69, where itdivides and exactly one half flows through the filament oi the Piranitube 55 to the corner I54 of said bridge.

The other half of the current flows through the common conductor I55,snap switch 15, conductor I-Gl, adjusted resistance 14, that is the partof said resistance after the lower end section I59 has been cut out, andback to the other corner I68. Inasmuch as this makes equal thepotentials at the corners I54 and I68, no current flows through themilliammeter relay 12, so that the hand 1l thereof drops back to contactpoint 15, thereby short circuiting the Dunco relay magnet winding I53through conductor I69, conductor l1l, conductor I12, azc ductor I13 andconductor I55. This allows tn rmature I50 of said magthe circuit throughthe "open lead I55 and closing the circuit through the "close lead I14.

The operating circuit to the motor 52 for closing movement of the valve5l is from line conductor 55 through conductor l4l, armature I54,

close lead I14, motor 52, "common" lead I51 and back to line 51 throughconductors I51 and I42. The circuits for each of the other adjustmentsof the snap switch are identical with those previously discussed. exceptthat conductor I55, I

I55 or I51 is used instead of conductor I5I- Apparatus C for controllingthe rectigon filament circuit, is operated by the photo-cell 55, thecathode I15 of said cell being connected to the grid I15 of relay tubeI11 through conductor I15, and the anode I15 of said cell beingconnected to plate l5l by means of conductor I82. The cathode heatingfilament I55 of the tube I11 isv energized from a secondary winding I54of transformer I55, the primary I55 of which is connected to the lineconductors 55 and 51 by conductors I51 and I55, respectively. The gridI15 is biased with respect to the cathode I by means of secondarywinding I5I connected thereto through a condenser I52 and grid leak I95.In operation, when the cathode I15 of the cell starts to emit electrons,upon the impingement of light thereon, the tube I11 passes more platecurrent induced by secondary winding I54 of the transformer I55, causingthe winding of relay magnet I55 to draw the armature I51 thereof toclose a circuit through conductors I55 and I55, from conductors I51 andI55, respec tively, through the winding of relay magnet 20l, to move thearmature 202 thereof to close the circuit to the primary winding 201 ofthe filament heating transformer 45, and connect the midpoint of thesecondary winding 200 for the filament 255 of thyratron 204 to line 51,through conductor 205. The plate 2I0 of the thyratron 204 is connectedto the controlled circuit between the resistance 205 and the primary 201by conductor 225. The thyratron grid 2 is actuated by variations in theline feeding the primary 201 of said filament transformer 45 throughconductors I51 and I58.

The resistance 205 across the secondary 200 adjustably connected to thegrid through the resistance 2l2, controls the potential of the grid 2ll, and is set so as to be just below the blocking point of the tube 204.This means that the plate current through the tube 204 is in parallelwith that through the resistance 205, reducing the efl'ective resistancein series with the primary 201 to a minimum, and allowing a maximumvoltage to be applied to said primary winding. The purpose of ourfilament voltage stabilizer is to guard against an increase in thepotential to the filament transformer. If the voltage of the linefluctuates above normal, the bias of the grid 2 becomes more negativewith respect to the plate causing the tube 254 to block, thus increasingnet to drop from its .liliitil'l'iOSt position, opening the effectivevalue of the resistance in series with the primary winding 201 which isthen simply the resistance 205, and effecting an adjustment of thefilament current by lowering the effective potential thereof.

Apparatus D for controlling the rectlgon plate circuit is operated. bythe photo-cell 54, the cathode 2I5 of said cell being connected to thegrid 2 of relay tube 2l5 by conductor 2I6, and the anode 2l1 of saidcell being connected to the plate 2l5 by means of conductor 2I9. Thecathode heating filament 22I of the tube 2I5 is energized from asecondary winding 222 of transformer 223, the primary 224 of which isconnected to the line conductors 66 and 61 by conductors 225 and 226,respectively. The grid 2 is biased with respect to the cathode 221 bymeans of secondary winding 228, connected thereto through a condenser228 and grid leak 23l.

In operation, when the cathode 2l3 of the cell 54 starts to emitelectrons upon the impingement of light thereon, the tube 215 passesmore plate current induced by secondary winding 232 of the transformer223, causing the winding of relay magnet 233 to draw the armature 234thereof, to close a circuit through conductors 235 and 236 from the lineconductors 66 and 61, through the winding of relay magnet 231', to movethe armature 238 thereof to close the plate circuit to the rectigcns IIto l1, inclusive, through the stabilizing resistance 238 and the lowresistance or voltage portion 2 of autotransformer of auto-reactance242.

A thyratron tube 243 is connected across the high voltage leads of saidauto-transformer 242, To accomplish this, conductor 244 connects oneside' of said'high voltage winding of said autotransformer 242 to thecenter tap, preferably, of secondary winding 245 which energizes thefilamentary cathode 246 of said thyratron 243.' The plate 241 of saidthyratron'is, in turn, connected by conductor 248 to the other highvoltage tap of said auto-transformer 242. The thyratron grid 248 isbiased with respect to the cathode 246 by secondary 25| oi transformer223, across whichis disposed a resistance 252, adjustably coupled to oneside of the resistor 238 through conductor 266. The grid 249 isconnected through grid leak resistance 253 to resistance. 238' throughconductor 218. The potential to the grid 248, through krid leak 253, isvaried in accordance with the voltage drop through the resistance 238,as the plate current through the rectigons varies.

In order to operate as desired, the current through the rectigons II toH, inclusive, on the exhaust, is set to theproper value for the desiredplate bombardment, after which the grid bias on the control tube. 243 isset at a relative potential just below the blocking point, that is, sothat the tube transmits current which acts as a short circuit across thereactance 242. The voltage drop through the series resistance 238 thenacts through the conductors 268 and 216 in such a manner as to make thegrid bias more negative and cause the tube 243 to block, when anincrease in the current is caused by some condition, either an increasein the line voltage or a decrease in the resistance of the dischargepath through the tubes II to l1, inclusive.

When the tube 243 blocks or stops discharging, it removes the shortcircuit or shunt path across the high voltage leads of the reactance242, and increases the eifect of said reactance in series in therectigon plate circuit, so that the current thereto is eifectivelycontrolled to prevent it from reaching excessive values, v

From the foregoing disclosure, it will be seen that we have provided amethod and apparatus for automatically initiating and controlling theexhausting and gas-filling steps, as well as the operating currents usedduring the manufacture of discharge devices. Although the disclosure isspecifically with regard to the making of rectigons, it is obvious thatwe do not wish to be limited thereto, as our invention is similarlyuse.. ful, at least to some extent, in the manufacture of any evacuated,gas-filled, or discharge device, as it, conserves the operators time andenergy by making at least some of the. manufacturing steps automatic,rather than manual,

' though in manufacturing some devices, it will be understood that someof the advantages of our invention may be obtained even though all ofthe elements of the apparatus disclosed are not.

used. The first, or primary apparatus, is that for connecting anddisconnecting, or controlling, the vacuum system. The second, is thatfor initiating and terminating, or controlling the admission of the fillgas, if used, and the regulation of the gas pressure. The third, is thatfor initiating, terminating, and controlling the filament or cathodeheating current in the devices, if devices including hot cathodes arebeing manufactured, The fourth is that for controlling the dischargecurrent through the devices, if discharge devices are beingmanufactured. The fifth, is thetemplet provided with slits for admittinglight to devices, such as photo-electric cells, which initiate andterminate the operation of the previously mentioned tube. devices, andthe sixth is the timer or templet driver, preferably motor driven, witha clutch drive, and also adapted to be hand operated, so that thetemplet may be operated at the desired speed. The timer desirably startsupon pushing a button, and automatically stops when the cycle has beencompleted.

In the preceding description of the apparatus, it will be understoodthat although a certain type of valve has been shown as employed in thevacuum and gas-filling supply lines, yet other types of valves or stopcocks may instead be efiectively employed, as the apparatus is merelyillustrative.

The motors or other means for operating such valves or stop cocks, aredesirably of the limit switch type, that is, when the prime moveroperates the valve or cook to fully open position, it automaticallyshuts ofi its own power, and the same thing occurs when it reverses andcompletely closes the valve.

It will also be understood, that although a Pirani tube has been shownfor controlling the pressure of the gas with which the devices arefilled, another suitable pressure sensitive device may be substituted,if desired. Although a snap switch on the gas valve motor has beenillustrated for regulating the resistance in parallel with the Piranitube filament for controlling the gas pressure, it will be understoodthat other suitable means may be substituted forthis purpose, ifdesired.

Although a preferred embodiment of our invention has been disclosed, itwill be' understood that modifications may be made within the spirit andscope of the appended claims,

We claim:

1. Amaratus for exhausting discharge devices comprising a valvecontrolling a vacuum connection, a motor for opening and closing saidvalve, 9. selecting relay for controlling the direction of operation ofsaid motor, a pair of initiating relays for said selecting relay, one ofsaid initiating relays being adapted to close a circuit to operate theselecting relay for causing the motor to turn in one direction and openthe valve, and the other relay being adapted to close another circuit toreturn the selecting relay to initial position and cause the motor tooperate in the opposite direction and close the valve, a threeelectrodetube for each initiating relay, a photoelectric cell for controllingeach three-electrode tube, and means automatically actuating said cellsat intervals in accordance with a manufacturing schedule.

2. Apparatus for gas-filling discharge devices comprising a valvecontrolling the admission of fill gas, a motor for opening and closingsaid valve, a snap switch actuated by movement of said motor, aselecting relay for controlling the direction of operation of saidmotor, an initiating relay for said selecting relay to eifect openingmovement of said valve, a three-electrode tube controlling the operationof said initiating relay, a photo-electric cell for actuating said tubeto cause the initiating relay to close, a. Wheatstone bridge, a Piranitube the filament of which is in circuit in one side of said bridge, aresistance in an adjacent side of said bridge, the adjustment of whLchis controlled by said snap switch, a relay connected to said bridge sothat a circuit is initiated thereby when the resistance of the Piranlfilamentbalances said adjusted resistance, in order to return theselecting relay to initial position and effect closing movement of saidvalve.

3. Apparatus for controlling the cathode heating filament current indischarge devices comprising a transformer with secondaries connected tothe filaments of said devices, means for preventing undesired increasein current in said filaments, upon an increase in the voltage applied tothe primary of said transformer, comprising a resistance in series withsaid primary, a three-electrode tube in parallel with said resistancefor controlling the effective voltage applied to said primary, means forclosing the circuit through said primary and eifec'ting the controlthereof, comprising an initiating relay, #1 other three-electrode tube,a relay in the tube plate circuit for effecting closing of saidinitiating relay, and a photo-electric cell, the electrodes of which arerespectively connected to the grid and plate of said tube for closingsaid last mentioned relay.

4. Apparatus for controlling the anode current of discharge devicescomprising anode and cathode connections to a source of powerforsupplying such current, means for controlling the intensity of saidcurrent comprising a resistance and auto-reactance in serieswith thecircuit, a three-electrode tube in parallel with said auto-reactance,means for varying the potential of the tube grid in accordance with theintensity of the discharge to cause the tube to block upon increase incurrent above normal, means for closing the discharge circuit andputting the control in effect, comprising an initiating relay, thearmature of which is adapted to close the line circuit, another relaycontrolling the circuit to the first mentioned relay, a threeelectrodetube controlling the operation of said last mentioned relay, and aphoto-electric cell the electrodes of which are respectively connectedto the plate and grid of said controlling tube for operating its relay.I

5. Apparatus for exhausting, gas filling, and operating dischargedevices. comprising a manifold to which said devices are connectedthrough their exhaust tubes, means for controlling the vacuum connectionto said manifold, means including a Pirani tube and a Wheatstone bridgefor controlling the gas connection to said manifold, means forinitiating and controlling the filament heating current of said devices,means for initiating and controlling the discharge current through saiddevices, photo-electric cells for controlling all of said means, meansfor controlling theoperation of said photo-electric cells in accordancewith a manufacturing schedule comprising a templet formed with slits, asource of light associated with said templet, and means for moving saidtemplet to expose the photo-electric cells to said source of light inaccordance with said schedule, in order to automatically eflectexhausting and gas-filling, initiate and control the filament current,and initiate and control the discharge current through said devices.

6. Apparatus for exhausting and gas filling discharge devices,comprising a manifold to which said devices are connected through theirexhaust tubes, a vacuum valve controlling a vacuum connection to saidmanifold, a vacuum motor for opening and closing said vacuum valve, aselecting relay for controlling the direction of operation of saidmotor, a pair of initiating relays for said selecting relay, athree-electrode tube for actuating one of said initiating relays foreffecting opening movement of said valve, another three-electrode tubefor actuating the other of said initiating relays for effecting closingmovement of said valve, a pair of photoelectric cells respectivelycontrolling said threeelectrode tubes, a gas valve controlling theadmission of fill gas to said manifold, a gas motor 'for opening andclosing said gas valve, a snap switch actuated by movement of said gasmotor, another selecting relay for controlling the direction ofoperation of said gas motor, another initiating relay for said selectingrelay, in order to effect opening movement of said valve, anotherthree-electrode tube controlling the operation of said initiating relay,another photo electric cell for actuating said last-mentioned tube tocause its initiating relay to close, a Wheatstone bridge, a Pirani tube,the filament of which is in circuit in one side of said bridge, aresistance in an adjacent side of said bridge, the adjustment of whichis controlled by said snap switch, a relay connected to said bridge sothat a circuit is initiated thereby when the resistance of the Piranifilament balances said adjusted resistance, in order to return theselecting relay to initial position and effect closing movement of saidgas valve, a templet formed with slits arranged in accordance with agiven schedule, a source of light associated with said templet, andmeans for moving said templet to expose all of the photo-electric cellsto light coming through said slits, to automatically effect exhaustingand gas-filling of said devices.

'1. Apparatus for exhausting discharge devices comprising a vacuumconnection, a device for opening and closing said connection, selectingmeans for controlling the direction of operation of said device,initiating means for said selecting means, one of said initiating meansbeing adapted to operate the selecting means for causing the device toopen the connection, and another of said initiating means being adaptedto return the selecting means to initial position and cause the deviceto operate in the opposite direction and close the connection, .acontrol tube for each initiating means, and a photo-electric cell foractivating each control tube, and means automatically actuating saidcells at intervals in accordance with a manufacturing schedule.

8. Apparatus for gas-filling discharge devices comprising a gas-fillingconnection, a device for opening and closing said connection,resistanceadjusting means actuated-by movement of said device, selectingmeans for controlling the direction of operation of said device,initiating means for saidselecting means to eflect opening movement ofsaid connection, a control tube for said initiating means, aphoto-electric cell for actuating said tube to cause the initiatingmeans to close, a Wheatstone bridge, a pressure-sensitive device incircuit in one side of said bridge,

a resistance in an adjacent side of said bridge, the I value of which iscontrolled by said adjusting means, means connected to said bridge sothat a circuit -is initiated when the resistance of thepressure-sensitive device balances said resistance, in order to returnthe selecting means to initial position and effect closing of I. saidconnection.

ing initiating means, another control tube, a relay in the tube platecircuit for efiecting closing of said'initiating means, and aphotoelectric cell, the electrodes of which are respectively connectedto the grid and plate of said tube for closing said last mentionedrelay.

10. Apparatus for controlling the anode current of discharge devicescomprising anode and cathode connections to a source of power forsupplying such current, means for controlling the intensity of saidcurrent comprising a resistance and auto-reactance in series with thecircuit, a control tube in parallel with said autoreactance, means forvarying the potential of the tube grid in accordance with the intensityof the discharge to cause the tube to block upon increase in currentabove normal, means for closing the discharge circuit and putting thecontrol in effect, comprising another control tube, and a photo-electriccell the electrodes of which are respectively connected to the plate andgrid of said control tube for operating said relay.

11. Apparatus for exhausting, gas filling, and operating dischargedevices, comprising means for controlling the vacuum connection, meansincluding a Pirani tube and a Wheatstone bridge for controlling the gasconnection, means for initiating and controlling the filament heatingcurrent of said devices, means for initiating and controlling thedischarge current through said devices, photo-electric cells forcontrolling all of said means, and means for automatically controllingthe operation of said photo-electric cells in accordance with amanufacturing schedule,

gas-filling, initiate and control the filament cur-- rent, and initiateand control the discharge current through said devices.

12. Apparatus for exhausting and gas filling discharge devices,comprising means for controlling the vacuum connection, means includinga Pirani tube and a Wheatstone bridge for controlling the gasconnection, photoelectric cells for controlling both of said means, andmeans for automatically controlling the operation of said photoelectriccells in accordance with a manufacturing schedule, in order toautomatically effect exhausting andgas filling of said devices.

13. Apparatus for operating discharge devices, comprising means forinitiating and controlling the filament heating current of said devices,

means for initiating and controlling the disanother photoelectric cell,

charge current through said devices, photoelectric cells for controllingboth of said means, and means for automatically controlling theoperation of said photoelectric" cells in accordance with amanufacturing schedule, in order to automatically initiate and controlthe filament cureffecting the control thereof, comprising an initiatingrelay, another three-electrode tube, a relay in the plate circuit of thelast-mentioned tube for eflecting closing of said initiating relay, theelectrodes of which are respectively connected to the grid and plate ofsaid last-mentioned tube for closing said last-mentioned relay, plateand filament connections to a source of power for causing a dischargecurrent to pass through said devices,

means for controlling the intensity of said curin order to automaticallyefiect exhausting and rent comprising a resistance and auto-reactance inseries with said power source, a thyratron tube in parallel :with saidauto-reactance, means for varying the-potential of the thyratron tubegrid, in accordance with the intensity of the discharge, .to cause saidthyratron tube to block upon increase in current above normal, toprevent excessive discharge means for closing the discharge circuit andputting the control in effect comprising an initiating relay for closingthe line circuit, another relay controlling the circuit to saidfirst-mentioned relay, another three-electrode tube controlling theoperation of said last-mentioned relay, a photoelectric cell,--

the electrodes of which are respectively connected to the plate and gridof said last-mentioned tube for operating its relay, a templet formedwith slits arranged in accordance with a given schedule, a source oflight associated with said templet, and means for moving the latter toexpose said cells to light coming through said slits to automaticallyinitiate and control the filament current, and initiate and control thedischarge current through said devices.

JAIHES H. GREEN. GEORGE H. ST. JOHN.

